<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>04CSS色值与背景</title>
    <style>
        .d1{
        }
        .d2{
        }
        .d3{
        }
    </style>
</head>
<body>
<h1>测试颜色</h1>
<div class="d1"></div>
<div class="d2"></div>
<div class="d3"></div>
</body>
</html>